# CVE-2026-83845: Windows Internet (wininet.dll) Spoofing Vulnerability


- **Severity:** High 8.4 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N/E:U/RL:O/RC:C`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 13 Oct 2026
- **Updated:** 29 Oct 2026
- **Also known as:** GHSA-pp9h-jmw7-x6cw

## What is CVE-2026-83845?

CVE-2026-83845 is a high-severity vulnerability in Microsoft Windows 10 21h2, published on 13 Oct 2026. 

### Official description

Improper privilege management in Windows Internet (wininet.dll) allows an authorized attacker to perform spoofing locally.

Weakness: CWE-290 (Authentication Bypass by Spoofing)

## Which versions are affected by CVE-2026-83845?

It affects 9 products.


Products: Microsoft Windows 10 21h2, Microsoft Windows 10 22h2, Microsoft Windows 11 23h2, Microsoft Windows 11 24h2, Microsoft Windows 11 25h2, Microsoft Windows 11 26h1, Microsoft Windows 11 26h2, Microsoft Windows Server 2022, Microsoft Windows Server 2025.

## How do I fix CVE-2026-83845?

No fix has been published for CVE-2026-83845 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-83845 being exploited?

There is no known exploitation of CVE-2026-83845 in the wild and no public exploit code.

## Other vulnerabilities in Microsoft Windows 10 21h2

- [CVE-2025-21333](https://insights.sbomify.com/CVE-2025-21333/): Microsoft Windows Hyper-V NT Kernel Integration VSP Heap-based Buffer Overflow (high 7.8, exploited in the wild)
- [CVE-2025-21334](https://insights.sbomify.com/CVE-2025-21334/): Microsoft Windows Hyper-V NT Kernel Integration VSP Use-After-Free (high 7.8, exploited in the wild)
- [CVE-2025-21335](https://insights.sbomify.com/CVE-2025-21335/): Microsoft Windows Hyper-V NT Kernel Integration VSP Use-After-Free (high 7.8, exploited in the wild)
- [CVE-2026-42904](https://insights.sbomify.com/CVE-2026-42904/): Windows TCP/IP Elevation of Privilege Vulnerability (critical 9.6)
- [CVE-2026-105733](https://insights.sbomify.com/CVE-2026-105733/): Windows Hyper-V Remote Code Execution Vulnerability (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-83845 and fix it if it is affected.

What it is: CVE-2026-83845 is a high-severity vulnerability in Microsoft Windows 10 21h2, published on 13 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-83845 in the wild and no public exploit code.

Affected product: Microsoft Windows 10 21h2. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-83845/ (Markdown: https://insights.sbomify.com/CVE-2026-83845/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-83845
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-83845
- OSV: https://osv.dev/vulnerability/CVE-2026-83845

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-83845/
Summaries are generated and may contain mistakes; the official description above is the record.